JPS63178410A - Slick polyurethane insulated wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a slippery polyurethane insulated wire that can be drawn out at high speed.

[Conventional technology]

Insulated wires are coated with a polyurethane paint containing polyol components and polyisocyanate components dissolved in organic solvents such as phenol, cresol, and xylenol and baked onto the conductor to prevent processing deterioration during coil winding and breakage during unwinding. Usually, a liquid lubricant such as liquid paraffin or refrigerating machine oil is applied on the insulation film to improve the windability.

However, recently, when this is used for coils that have a structure in which the entire relay drive mechanism is enclosed in a sealed case, which is especially used for small relay coils, liquid lubricant on the surface of the coating and residual in the coating may be removed. During relay operation, the solvent components in the plastic case evaporate and fill the plastic case, and adhere to the relay contacts, increasing contact resistance. Furthermore, the arc generated when the contacts open and close decomposes this organic gas, and the generated carbon adheres to the contacts, resulting in longer arc durations and faster wear of the contacts.

[Problem that the invention seeks to solve]

In order to prevent the effects of this liquid lubricant and residual solvent in the coating, conventional methods include vacuum heating treatment of relay coils, and high paint baking temperatures and long drying times to ensure sufficient solvent scattering. Measures such as these are being taken. However, the former method cannot completely prevent the generation of organic gas, and requires vacuum equipment, which increases the number of work steps. Moreover, the latter means lowers the productivity of the wire and is not an advantageous solution. Therefore, in the past, in order to prevent relay contact failures, the only option was to limit the amount of liquid lubricant applied to the surface of the film as much as possible (there were problems with the high-speed feeding of the wire).

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides self-lubricating properties to the insulating film itself without applying a lubricant to the surface of the insulating film. The present invention has succeeded in providing a polyurethane insulated wire that can prevent the generation of solvent gas as much as possible and has stable high-speed unwinding properties.

Polyethylene,
Polyolefin-based synthetic resins such as polybrene, low molecular weight linear resins or waxes, beeswax, carnauba wax,
Techniques for imparting self-lubricating properties to coating films by adding solid waxes such as montan wax are conventionally known. However, these solid lubricants are insoluble or poorly soluble in general-purpose organic solvents, making it difficult to uniformly disperse them in paints, and even if they can be dispersed, the stability of the paint is poor (and may deteriorate over time). Another drawback is that the felt-based paint application method, which uses capillary action, causes layer separation.
When the paint penetrates inside the felt, gel-like solid lubricant gets trapped in the internal mesh and becomes clogged, and the permeability of the paint gradually worsens, making it impossible to form a specified film thickness. can be mentioned. In general, these solid lubricants have a long chain alkyl group in their molecules, have a small solubility parameter (SP value), and have a large molecular cohesive energy compared to polyurethane molecules. Since solid lubricants tend to bleed, we believe that if we can improve the compatibility between this lubricant and polyurethane paint by taking advantage of the unique properties of the film surface, all of the above problems can be solved. Therefore, the present invention has been made.

The solid lubricant targeted in the present invention has a molecular weight of 30
,000 and/or higher fatty acid esters and ethylene polymerized waxes having a molecular weight of around 5,000.

These solid lubricants are in the form of gels dispersed in organic solvents and are difficult to obtain. Generally, isopropyl alcohol, Kijirol, or a polymeric plasticizer is used as a dispersion medium, and the solid content is 20 to 30% by weight and the particle size is about 15 to 20 μm. However, if it is added to a polyurethane paint in this state, as described above, the compatibility is poor, and the film coated and baked on the conductor has a poor appearance, making it completely unusable.

For this reason, the present inventors first investigated means for dry-pulverizing these solid lubricants. However, the particle size of dry grinding is 3
There is a limit of about μm, and the new interface created by pulverization is chemically active and reacts with oxygen in the air, introducing active groups, improving compatibility with polyurethane paints, but on the other hand, it causes bleed. This impairs the properties of the coating, and the formation of a slippery thin film that occurs during coating film formation becomes worse. Therefore, in the present invention, a solid lubricant dispersed in an organic solvent is wet-pulverized in this solvent to form a dispersion of fine powder lubricant in order to modify the lubricant. The fine powder lubricant dispersion has very good compatibility with the polyurethane insulation coating. The wet-pulverized fine powder lubricant has a particle size of 1.5 μm or less, preferably 0.5 μm.
Good results are obtained when the amount added to the paint is within the range of 0.1 to 5.0% by weight, preferably 0.5 to λO% by weight, based on the resin content of the polyurethane paint. .

[For production]

When a solid lubricant dispersed in an organic solvent is wet-pulverized,
A new highly active surface is generated, and interactions between particles occur through solvent molecules, improving affinity with polyurethane paint solvents, greatly improving dispersibility, and good bleedability. .

〔Example〕

I Preparation of Polyurethane Insulating Paint Based on the formulation shown in Table 1, add the polyol component and polyisocyanate component to the solvent using the usual method, and heat (70 to 8
0°C), stirred and dissolved to prepare a polyurethane insulation coating.

Table 1: Polyurethane paint composition ■ Wet pulverization of lubricant The solid lubricant and organic solvent were weighed in the proportions shown in Table 2, placed in a stainless steel vibrating mill container, and pulverized 24 hours a day.

Table-2 Wet pulverization of lubricant ■ Production of lubricating polyurethane insulated wire The polyurethane insulating paint and lubricant obtained based on Table-1 and Table-2 are combined in the composition shown in Table-3, and self-lubricating polyurethane paint is applied. was prepared. And this is conductor diameter 0
．． This was coated and baked on a 03ff copper wire to produce a slippery polyurethane insulated wire according to the present invention. As a comparative example, a conventional lubricating polyurethane coating was prepared by applying liquid paraffin, a liquid lubricant, on the insulation coating of a polyurethane insulated wire, which was coated with a polyurethane insulating paint that did not contain a lubricant and baked under the same conditions as in the example. It is an insulated wire.

Table 3: Blend composition of self-lubricating polyurethane paint Characteristics of slippery polyurethane insulated wire Table 4 shows the properties of the slippery polyurethane insulated wire obtained.

Table 4 Characteristics of slippery polyurethane insulated wire [Effects of the invention] As is clear from the performance results in Table 4, the slippery polyurethane insulated wire according to the present invention is superior to the conventional polyurethane insulated wire whose surface is coated with liquid paraffin. Compared to the above, it was possible to improve the lubrication properties without any loss in other properties. In other words, the dynamic friction coefficient μ is reduced to about half that of the conventional one, and it can be applied to high-speed windings of 1 tO00 rpm or more.
Especially when used as a winding for a small sealed relay coil,
It produces less organic solvent gas and has the effect of preventing relay contact failures as much as possible.

In order to prevent failure of the relay contacts, it is more effective to use an organic solvent mainly composed of a non-phenolic solvent such as Kijirol as the dispersion medium of the solid lubricant and the solvent of the polyurethane resin paint.

Claims (2)

[Claims] (1) Fine powder lubricant obtained by dispersing a solid lubricant selected from low molecular weight polyolefins, higher fatty acid esters, and/or ethylene polymerized waxes that are poorly soluble in organic solvents in the above organic solvent, and then wet-pulverizing them in this solvent. 1. A slippery polyurethane insulated wire, characterized in that a self-lubricating polyurethane insulating paint, in which a dispersion of the agent is added to a polyurethane resin paint, is applied and baked onto a conductor directly or via another insulating film. (2) The particle size of the wet-pulverized fine powder lubricant is 1.5μ
m or less, and the amount added to the polyurethane resin paint is within the range of 0.1 to 5.0% by weight of the solid content based on the resin content of the paint. Polyurethane insulated wire.